The present invention relates to a heat exchanger, such as a condenser coil for a household refrigerator.
In particular, the present invention is a condenser tube structure, and a method for forming a condenser tube structure, for a refrigerator, the condenser tube structure having secondary heat transfer surfaces.
Tubular condensers having extended secondary heat transfer surfaces are generally known, such as U.S. Pat. No. 3,785,168, which discloses wires (21) attached to tubes (20). However, this coil represents a refrigerant progression which is counterflow to the air flow direction only in an upper tier and is same direction flow in a lower tier.
U.S. Pat. No. 2,359,926 discloses a tubular evaporator for a refrigeration unit which utilizes a metal sheet for the extended surfaces.
Manufacturing a wire and tube condenser requires a costly amount of factory floor space, material handling, equipment and labor.
The "wire field" is an area in the factory associated with the condenser fabrication process presently known. Each of the current condenser welders uses approximately 130 individual strands of wire fed into the welder. Each of these strands originates from a spool of wire that requires about four square feet of floor space in the factory. These spools of wire are located in the wire field. A high level of labor is required to stock the wire, tend the spools as wire is removed, weld the ends of one strand of wire to a new spool, and remove the empty spools.
It is not known to provide a heat exchanger, and method of manufacture thereof, for a refrigerator using a folded tube coil with wire fins or a plate extended heat exchange surface in accordance with the present invention.